Receding door mechanism



Nov. 8, 1955 w. BELEW 2,723,177

RECEDING DOOR MECHANISM Filed Sept. 12, 1952 2 Sheets-Sheet 2 INVENTOR LELAND W. BELEW ATTOR NE Y5 Unite States Patent 2,723,177 Patented Nov. 8, 1955 fitice RECEDHJ G DOOR MECHANISM Leland W. Below, Hamilton, Ohio, assignor to Herring- Hall-Marvin Safe Company, Hamilton, Ohio, 3 corporation of Ohio Application September 12, 1952, Serial No. 309,254

4 Claims. (Cl. 312-322) The present invention relates to receding door units and has particular reference to means for adjustably mounting receding doors within compartments.

Heretofore inventors skilled in constructing receding door units have mounted heavy doors upon carriages which are designed to move upon rollers fore and aft of a receding door compartment. Present day constructions incorporate no elficiently workable means for overcoming distortional effects upon carriages which are brought about as a result of hinging a heavy protective door to a door carriage element. Normally, in such safe constructions, great friction is developed through the complexity of working parts arranged to carry and move the receding door. Abbott et al. in Patent No. 1,873,522 provided movable tension means which were secured to a carriage and engageable with a plurality of pulleys journalled at fixed points along the receding door compartment walls. Although useful, the complexity of the system caused undesirable forces of friction to build up and hamper eflicient use and the arrangement in this and related devices required much valuable space. Henkel sought to overcome the distortional forces in Patent No. 2,598,255 through the attachment of a roller to the rear of a carriage, the roller engaging an inverted track to counteract torque. It will be readily appreciated from the foregoing that a substantially wide carriage was required in such prior constructions. These and other problems gave rise to the device herein described.

In the present invention, the simplicity of the door carriage and working parts permits the construction of a safe or similar unit wherein the receding door compartment may be sufficiently small with respect to the utility chamber as to allow a plurality of safe units to be used together and side by side where perhaps only several could be used in the past. Moreover, this construction permits storage of the entire door without forward or rearward extension of the receding door compartment.

When a receding door is locked upon the utility chamber of a receding door cabinet, there is little, if any distortional force imposed upon the hinge and a carriage supporting the hinge of the door. Upon opening of the receding door, however, the door imposes downward and outward forces upon the hinge and some effort must be made within or upon the carriage to overcome such turning forces. In the present instance, a fulcrum member carries all weight of the receding door and carriage. As the distortional force or torque imposed upon the carriage by the door tends to rotate the carriage about the fulcrum in a counterclockwise manner, the distortional force is simultaneously transmitted from the fulcrum directly to a coaxially mounted pulley and to a second pulley joined to the first by a cable. The cable, fixed at its ends, and joining the pulleys, absorbs all of the torque and maintains the carriage in an upright position. The present pulley system supports none of the dead weight of the receding door or carriage, for actually, door torque is gathered by the cable and counteracted by anchor members provided at fore and aft stanchions of the receding door chamber on the floor and ceiling thereof, respectively.

It is, thus, an object of this invention to provide novel means for movably securing a receding door in a compartment through the utilization of a minimum number of working parts effecting the maximum in utility, efficiency at minimum construction, repair and replacement costs.

A further object of the invention is to develop a movable door carriage in a receding door compartment which is adapted to mount a majority of the working parts and to secure within a smallest housing space for the receding door and carriage.

Yet another object of the invention is to provide a simple leverage system to counteract the distortional torque imposed by a receding door upon a carriage designed to support such a door wherein frictional contact between working parts may be reduced to a minimum.

Yet another object of the invention is to provide a carriage for receding doors wherein novel leverage means employed in balancing the said carriage produces levelling means for the carriage and door.

An advanced object of the invention is to provide a novel receding door carriage construction which is light in weight, compact in size, adapted to contain a majority of working elements of a leverage and level adjusting system, and whereupon a single axle member may be adapted for coaxial mounting of leverage and fulcrum members.

The above and other objects of the invention will be readily apparent through reference to the succeeding drawings, description and claims defining theinvention. To more clearly define the invention, a series of drawings is appended hereto wherein:

Figure 1 is a View in perspective of a cabinet having a utility chamber and receding door compartment:

Figure 2 is a vertical sectional view of the invention taken along the lines aa of Figure 1, within the interior of the receding door compartment and showing the receding door working elements when the receding door is stowed;

Figure 3 is a view in side elevation as the receding door is closed upon the utility chamber showing the working elements of the invention in phantom;

Figure 4 is an expanded vertical sectional view taken along the line bb of Figure 3 showing a portion of the carriage and associated working parts.

Referring to the drawings wherein a preferred form of the invention is illustrated, there is shown in Figure 1, a receding door cabinet 10 having a receding door 11 adapted to close upon and secure a utility chamber 12. A receding door compartment 13 provided adjacent the utility chamber 12 is constructed to movably house the receding door 11 when the door is not in use as a closure member for the utility chamber 12. Here the receding door is partially housed.

The cabinet is shown to have roof 14 and a bottom portion or platform 15 forming the base of the cabinet. A rear wall 16 joins the roof to the platform and together with sidewalls 17, the shell structure of the device is complete.

In Figures 2 and 3, extending from front to rear of compartment 13 and suitably welded or otherwise secured to a reinforced section of roof 14, there is shown a beam 18. Beam 18 carries a depending right angled support member 19 having a downwardly projecting flange. Opposite the flange of support 19 is a fiat guide 20 held in parallel spaced relation to the flange preferably by means of spacers and carriage bolts 21 passing through the guide element 20 and secured in the flange portion of the angle 19.

A stanchion 22 is fixed at right angles to guide 20 between the guide and opposed flange and at a rearward extremity thereof. The stanchion 22 protrudes downwardly to form extension 23 for receiving an adjustable extension of a flexible linkage element 43. A corresponding stanchion is fixed to the lower frontal portion of the receding door chamber as at 25. This corresponding stanchion 25 is designed to engage the forward end of a horizontal guide member 28 extending fore and aft of the compartment 13. Stanchion 25 has a projection 26 extending upwardly from the floor of the chamber and preferably above the bearing surface of a track 29. This stanchion 25 serves not only as an anchor for a chain 48 which is secured to its projection but also as a fixed buffer for the movable carriage hereinafter described. A corresponding buffer stanchion 27 is provided at the upper forward extremity of the receding door chamber.

As best shown in Figure 4, a track 29, extending from front to rear of the receding door chamber, is secured to the guide 2% as by screw means or welding means. Track 29 is substantially heavier in construction with respect to parallel guide 28 since the track is adapted to engage and carry the main support of the receding door mechanism to conceal or otherwise completely house the receding door while the utility ch mber is open to use. A rearward bufier stanchion 30 is provided to retard and contain the carriage upon its rearwardmost movement within the receding door compartment.

In order that the receding door may be supported, a durable carriage 31 is provided. In Figures 3 and 4,

a selected solid flat walled construction is illustrated. Ar-

rows 32 and 33 indicate areas of the carriage most suitable for mounting working elements of the invention. Supporting T-hinge projections 34 and 35 are secured to the front portion of the carriage through a conventional shaft extending vertically through the projections.

lournalled in a horizontally projecting flange 37 and mounted in vertical extension of the carriage element 31 are a plurality of bearings 36. Bearings 36 engage guides 26, 28 and their corresponding opposites, respectively, to impart lateral stabilization to the carriage in movement.

Axles 38 and 39 pass through the carriage as in areas 33 and 32, respectively. Axle 3% comprises two complementary portions having different outer diameters. Since the most of the weight of the receding door, carriage and working elements is supported upon a single bearing, which bearing is carried by the axle member 39, the working portion of the axle member must be correspondingly more substantial than its extension which retains less stress. secured within an aperture as at 32 and extension 41, which is of diminished diameter with respect to support 40 of the axle, is adapted to secure pulley 47 in working engagement. At one end 42, the axle is threaded for engagement with a locking nut 43.

Between the lower pulley 4-7 and the securing washers there are spacers 44 and a sleeve 45 providing a rolling surface for pulley needle bearings 46. According to the arrangement shown in Figure 4, the linkage element 48 is adapted to pass under the axis of lower pulley 47 and over the axis of upper pulley 47. Since the horizontal distance from the center of mass of the door to the fulcrum is less than the vertical distance from lower pulley or fulcrum to upper pulley, there is obtained hereby a mechanical advantage in counteracting torque imposed by the door, the mechanical advantage varying with weight and disposition of parts. A preferred construction includes a door the width of which is one-half the height thereof. in such a construction, the center of weight of the door can be stated to be at the bottom center of the door. A line drawn along the bottom of the door from the center of weight thereof to the fulcrum could be considered as a horizontal arm of a lever. Another line drawn vertically upwardly from the fulcrum along the hinge could be considered as vertical 'arm of Carriage support 40 of axle 39 r a lever. At a point one quarter the height of the door, along the vertical arm, an amount of horizontal rearward pull, which is equal to the total force (weight) imposed on the horizontal arm at the base of the door is required to counteract torque on the fulcrum. At one half the distance up the vertical arm, which would be twice the length of the horizontal arm, a force one half as great as the force upon the horizontal arm is required. At the upper extremity of the hinge vertical arm, it follows that a horizontal force or pull which is one fourth the downward force (weight) upon the horizontal arm is required to counteract torque which is created by the hanging of the door.

As has been indicated, chain 48 is secured at its running ends to extensions of the respective stanchions 22 and 25. It is desirable to have the tension adjusting means for the chain disposed rearwardly with respect to the open portion of the receding door compartment, to allow minimum tolerance at the front of the compart- The extension of the chain is threaded as at 49 and is adapted to pass through the stanchion as at 23 to receive locking nut 50 and adjusting nut 51.

Turning to the construction embodied in the carriage element 31, and best shown in Figure 4, a rolling fulcrum 52: is journalled upon the carriage member 31 coaxially with the lower pulley as at 32. The inner spacer of the fulcrum 52, spacers 44 and sleeve 45 are fixedly united upon tightening the nut 43 of the axle. The fulcrum member bears upon track 29 and is adapted to pass the carriage member to the rearwardmost and forwardmost positions of the receding door chamber, said positions being defined by the abutments disposed upon stanchions at 25, 27 and 39, respectively. See Figure 3. it is noteworthy that the coaxial mounting of the fulcrum and lower pulley permits maximum forward displacement of the carriage.

To counteract the distortional torque imposed upon the carriage and more specifically upon the fulcrum member 52, the pulley members are adapted to effect the transmission of said forces to the said stanchions disposed respectively forwardly and rearwardly of the receding door chamber. Whereas the exact positioning of the pulley members with respect to the one another, which is shown, is not essential to efiicient functioning of the device, the preferred arrangement of parts for the present construction is presented. For convenience of manufacturing and for maximum leverage efiiciency, the coaxial mounting of the fulcrum and lower pulley is desirable. Moreover, the unique arrangement and simplicity in construction permit movement of ponderous receding doors with a minimum amount of application. For instance, a pull of four pounds is sufiicient to move a door weighing one hundred and eighty pounds outwardly from the compartment.

For horizontal adjustment of the receding door, shortening or lengthening of the linkage member 48 is required.

In operation, the receding door may be moved from its position of closure upon the utility chamber outwardly and simultaneously thrust rearwardly moving the entire assembly upon the rolling fulcrum 52 along track 29. Simultaneously the freely movable pulleys 47 will rotate about their respective axes over and under the chain which cooperates with the pulleys to counteract door torque. As the carriage is moved rearwardly, stability to the carriage is obtained, the stabilizers 36 engaging the guides which are placed parallel to the direction of movementof the carriage. Stabilizers 36 bear no weight, the entire weight being borne by the main support bearing. Moreover, virtually no dead weight is carried by the pulley or pulley system d7 since this system serves merely to counteract the distortional forces of the receding door on the carriage plate. Any weight which might be transferred to the pulley system is absorbed laterally by the stabilizers 36, and the carriage is allowed to move freely to and fro and without the usual excessive frictional forces retarding movement.

Whereas a preferred embodiment of the invention has been described in detail, the invention is not limited to the precise arrangement and relative size and conformation of parts described herein. It is to be noted that similar operational parts could be substituted in the preferred construction to achieve like results without departing from the spirit of the invention. The invention is limited only as defined in the appended claims.

I claim:

1. A cabinet of the type having a receding door comprising a shell, a receding door, a utility chamber within the shell having a forward open end for engaging said door, a compartment defined by the shell adjacent said utility chamber and having a forward open end to receive the door, a carriage for said door movably mounted within the compartment, a rolling fulcrum for the carriage mounted axially upon a lower forward portion of said carriage at one side of the carriage, a track for said rolling fulcrum, said track running horizontally fore and aft the compartment, a guide for the carriage, said guide being in vertical spaced relation and parallel to said track, a first pulley mounted coaxially with respect to the fulcrum and on another side of the carriage and a second pulley mounted vertically readwardly of the first said pulley and in the same plane as the first said pulley, a flexible cable for engaging the pulleys and counteracting torque imposed upon the carriage, a first tie secured to a forward portion of the track, and a second tie secured to a rearward portion of the guide, said cable being secured at its ends to said first tie and said second tie, and an adjustable tension element secured to one end of said chain for adjustable contact with one of said ties.

2. In a device of the character described in claim 1, an axle for the rolling fulcrum and for the coaxially mounted first said pulley, comprising a head, a shaft secured to the head of said axle to bear the rolling fulcrum, and an extension of decreased diameter with respect to the shaft to bear the first said pulley.

3. A cabinet having a receding door comprising a shell,

a utility chamber within said shell, a receding door compartment defined by the shell and located adjacent to said utility chamber, a receding door for said utility chamber, an upright carriage for the receding door movably mounted within the said receding door compartment and hingedly connected to the door, a track laid horizontally within a lower portion of said receding door compartment and running from front to rear of the compartment, a first guide in horizontal spaced relation and parallel to the track, a second guide secured to an upper portion of the compartment, said second guide consisting of a pair of rails depending from the upper portion of the compartment and running fore and aft thereof, a rolling fulcrum mounted upon one side of a lower forward portion of said carriage for movement of the carriage upon the track and fore and aft said receding door compartment, a first pulley coaxially mounted with respect to said fulcrum and upon another side of said carriage, an axle upon the carriage passing through said fulcrum and said first pulley journalling said first pulley and said fulcrum to opposite sides of said carriage, a second pulley journalled to an upper rearward portion of said carriage on the same side of the carriage as the first pulley, a cable for engaging each said pulley, said cable having ends, ties secured to said guides for anchoring ends of the cable, said cable passing beneath the lower pulley and over the upper pulley to transfer receding door torque upon the carriage to the said anchors thereby to counteract receding door torque upon the upright carriage.

4. In a device of the type defined in claim 3, an adjusting extension upon at least one running end of the said cable whereby increased and reduced tensions upon the cable will effect horizontal disposition of the said receding door.

References Cited in the file of this patent UNITED STATES PATENTS 296,629 Sanders Apr. 8, 1884 1,008,987 Prouty Nov. 14, 1911 1,513,849 Moore Nov. 4, 1924 1,873,522 Abbott Aug. 23, 1932 2,598,255 Henkel May 27, 1952 

